BR112014012335B1 - AEROSOL GENERATOR ELECTRIC SMOKING DEVICE AND METHOD FOR DETECTING A USER INHALATION - Google Patents

Abstract

AEROSOL GENERATOR DEVICE AND METHOD FOR DETECTING A USER INHALATION. The present invention relates to an aerosol generating device configured for user inhalation of a generated aerosol, the device comprising: a heating element configured to heat an aerosol-forming substrate; a power source connected to the heating element; and a controller connected to the heating element and the power source, where the controller is configured to control the energy supplied to the heating element from the energy source to maintain the temperature of the heating element at a target temperature, and is set to monitor changes in the temperature of the heating element or changes in the energy supplied to the heating element to detect a change in airflow after the heating element indication of a user inhalation. The controller can determine when a user has inhaled and can use this for dynamic control of the device, as well as provide user inhalation data for subsequent analysis.

Description

[001] The present invention relates to aerosol generating systems and, in particular, aerosol generating devices for the user's inhalation, such as smoking devices. The specification refers to a device and a method for detecting changes in airflow through an aerosol generating device that normally corresponds to a user's inhalation or aspiration, in a cost-effective and reliable manner.

[002] Cigarettes lit at the end release smoke as a result of the combustion of tobacco and a wrapper that occurs at temperatures that can exceed 800 degrees Celsius during aspiration. At these temperatures, tobacco is thermally degraded by pyrolysis and combustion. The heat of combustion releases and generates the gaseous combustion products and tobacco distillates. The products are extracted through cigarettes and cooled and condense to form a smoke that contains the flavors and aromas associated with smoking. At combustion temperatures, not only are flavors and aromas generated, but also a number of undesirable compounds.

[003] Electrically heated smoking devices are known, which are essentially aerosol generating systems, which operate at lower temperatures than conventional lit cigarettes. An example of such an electric smoke device is described in WO2009 / 118085. WO2009 / 118085 discloses an electric smoke system, in which an aerosol-forming substrate is heated by a heating element to generate an aerosol. The temperature of the heating element is controlled to be within a certain temperature range, in order to ensure that undesirable volatile compounds are not generated and released from the substrate, while other desired volatile compounds are released.

[004] It is desirable to provide an aspiration detection function in an aerosol generating device in a cheap- and reliable way. Aspiration detection is useful, for example, for the dynamic control of a heating element inside the system and, for analytical purposes.

[005] In one aspect of the specification, an aerosol generating device configured for user inhalation of a generated aerosol is presented, the device comprising:

[006] a heating element configured to heat an aerosol-forming substrate;

[007] an energy source connected to the heating element; and

[008] a controller connected to the heating element and the power source, where the controller is configured to control the energy supplied to the heating element of the energy source to maintain the temperature of the heating element at a target temperature, and is configured to monitor changes in the temperature of the heating element or changes in the energy supplied to the heating element to detect a change in airflow by the heating element indicative of a user inhalation.

[009] As used herein, a "sun aerosol generating device" refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol forming substrate can be part of an aerosol generating article, for example, part of a smoke article. An aerosol generating device may be a smoking device, which interacts with an aerosol-forming substrate of an aerosol generating article to produce an aerosol that is directly inhaled into a user's lungs through the user's mouth. An aerosol generating device can be a support.

[0010] As used herein, the term "aerosol-forming substrate" refers to a substrate capable of releasing volatile compounds that can form an aerosol. Such volatile compounds can be released by heating the aerosol-forming substrate. An aerosol-forming substrate may conveniently be part of an aerosol-generating article or a smoke article.

[0011] As used herein, the terms "aerosol generating article" and "smoke article" refer to an article comprising an aerosol-forming substrate that is capable of releasing volatile compounds that can form an aerosol. For example, an aerosol generating article may be a smoking article that generates an aerosol that is directly inhaled into a user's lungs, through the user's mouth. An aerosol generating article may be disposable. The term "smoking article" is generally used later. A smoking article may be, or may comprise, a tobacco rod.

[0012] As used herein, the term "inhalation" is intended to mean the action of a user to aspirate an aerosol into his body through his mouth or nose. Inhalation includes the situation in which an aerosol is aspirated into the user's lungs, as well as the situation in which only one aerosol is aspirated into the user's mouth or nasal cavity, before being expelled from the user's body.

[0013] The controller can comprise a programmable microprocessor. In another embodiment, the controller may comprise a dedicated electronic chip, such as a Field Programmable Gate Array (FPGA) or a specific application integrated circuit (ASIC). In general, any device capable of providing a signal capable of controlling a heating element can be used according to the modalities discussed here. In one embodiment, the controller is configured to control the difference between the temperature of the heating element and the target temperature to detect a change in air flow by the heating element indicative of a user inhaling.

[0014] The specification presents the detection of changes in air flow through an aerosol generating device and, in particular, the detection of inhalations or user aspirations, without the need for a dedicated air flow sensor. This reduces the cost and complexity of user inhalation detection mode compared to existing devices, which include a dedicated airflow sensor, and increases reliability since there are fewer components that can potentially fail.

[0015] In one embodiment, the controller can be configured to monitor whether the difference between the temperature of the heating element and the target temperature exceeds a limit, in order to detect a change in air flow by the heating element indicative of an inhalation of user. The controller can be configured to check whether the difference between the temperature of the heating element and the target temperature exceeds a limit for a predetermined period of time, or by a predetermined number of measurement cycles to detect a change in airflow through the element of heating indicative of a user inhalation. This ensures that fluctuations in a very short time do not lead to the false detection of a user inhalation.

[0016] In another mode, the controller can be configured to monitor the difference between the energy supplied to the heating element and a standby energy level to detect a change in the air flow by the heating element indicating an inhalation of the user. Alternatively, or in addition, the controller can be configured to compare a rate of change of temperature, or a rate of change of the supplied energy, with a threshold level to detect a change in air flow by the heating element indicative of an inhalation of user.

[0017] The controller can be configured to adjust the target temperature when a change in airflow after the heater is detected. The increased air flow brings more oxygen into contact with the substrate. This increases the likelihood of combustion of the substrate at a given temperature. Combustion of the substrate is undesirable. Thus, the target temperature can be reduced when an increase in airflow is detected, in order to reduce the likelihood of combustion of the substrate. Alternatively, or in addition, the controller can be configured to adjust the energy supplied to the heating element when a change in airflow after the heater element is detected. The flow of air after the heating element typically has a cooling effect on the heating element. The energy for the heating element can be temporarily increased to compensate for that cooling.

[0018] The power source can be from any suitable power source, for example, a DC voltage source, such as a battery. In one embodiment, the power supply is a lithium-ion battery. Alternatively, the power source can be a nickel metal hydride battery, a nickel-cadmium battery, or a lithium-based battery, for example, a lithium-cobalt, lithium-iron-phosphate battery or of lithium polymer. Power can be supplied to the heating element as a pulsed signal. The amount of energy supplied to the heating element can be adjusted by changing the duty cycle, or the pulse width of the energy signal.

[0019] In one mode, the controller can be configured to monitor the temperature of the heating element based on a measurement of the electrical resistance of the heating element. This allows the temperature of the heating element to be detected without the need for additional detection equipment.

[0020] The heater temperature can be monitored at predetermined time intervals, such as every few milliseconds. This can be done continuously or only during periods when energy is being supplied to the heating element.

[0021] The controller can be configured to restore, ready to detect the next user aspiration when the difference between the detected temperature and the target temperature is less than a limit value. The controller can be configured to require that the difference between the detected temperature and the target temperature be less than a threshold value over a period of time or the predetermined number of measurement cycles.

[0022] The controller can include a memory. The memory can be configured to record changes detected in the user's airflow or aspirations. The memory can record a count of user aspirations or the time of each aspiration. The memory can also be configured to measure the temperature of the heating element and the energy supplied during each suction. The memory can store all available data from the controller, if applicable.

[0023] This user aspiration can be useful for further clinical studies, as well as for device maintenance and design. The user's aspiration data can be transferred to an external memory, or a device for processing any suitable data output means. For example, the aerosol generating device may include a wireless radio connected to the controller or memory or a universal serial bus (USB) connected to the controller or memory. Alternatively, the aerosol generating device can be configured to transfer data from the memory of an external memory of a battery charging device each time the aerosol generating device is recharged through suitable data connections.

[0024] The device can be an electrical smoking device. The aerosol generating device may be an electric heating smoke device comprising an electric heater. The term "electric heater" refers to one or more elements of electric heating.

[0025] The electric heater may comprise a single heating element. Alternatively, the electric heater may include more than one heating element. The heating element or heating elements can be arranged appropriately in order to more effectively heat the aerosol forming substrate.

[0026] The electric heating element can comprise an electrically resistive material. Suitable electrically resistive materials include, but are not limited to: semiconductors, such as ceramics, doped ceramics, electrically "conductive" ceramics (such as, for example, molybdenum disilicate), carbon, graphite, metals, metal alloys and composite materials produced from a ceramic material and a metallic material. Such composite materials can comprise doped or non-doped ceramics. Examples of suitable doped ceramics include doped silicon carbides. Examples of suitable metals include titanium, zirconium, tantalum and platinum group metals. Examples of suitable metal alloys include stainless steel, nickel, cobalt, chrome, aluminum and titanium, zirconium, hafnium, niobium, molybdenum, tantalum, tungsten, tin, gallium, manganese, gold and alloys containing iron, and base alloys. nickel, iron, cobalt, stainless steel, Timetal® and iron, manganese and aluminum based alloys. In composite materials, the electrically resistive material can optionally be incorporated, encapsulated or coated with an insulating material and vice versa, depending on the energy transfer kinetics and the required external physical-chemical properties. Ceramic and / or insulating materials can include, for example, aluminum oxide or zirconium oxide (ZrO2). Alternatively, the electric heater may comprise an infrared heating element, a photonic source, or an inductive heating element.

[0027] The electric heating element can take any suitable shape. For example, the electric heating element can take the form of a heating blade. Alternatively, the electric heating element can take the form of a housing or substrate that has different electroconductive portions, or an electrically resistive metal tube. Alternatively, one or more heating needles or rods that are extended through the center of the aerosol forming substrate can be as previously described. Alternatively, the electric heating element may be a disc heater (end) or a combination of a disc heater with heating needles or rods. Other alternatives include a heating wire or filament, for example, a Ni-Cr (nickel-chromium), platinum, gold, silver, tungsten or alloy wire, or a heating plate. Optionally, the heating element can be deposited on or on a rigid support material. In such a modality, the electric resistance heating element can be formed using a metal that has a definite relationship between temperature and resistivity. In such an example device, the metal can be formed as a strip of a suitable insulating material, such as ceramic material, and then glued to the other insulating material, such as glass. Heaters formed in this way can be used both to heat and to control the temperature of the heaters during operation.

[0028] The electric heater may comprise a heat sink, or heat reservoir that comprises a material capable of absorbing and storing heat and subsequently releasing heat over time to the aerosol-forming substrate. The heat sink can be formed of any suitable material, such as a suitable metal or ceramic material. In one embodiment, the material has a high heat capacity (sensitive heat storage material), or is a material capable of absorbing and subsequently releasing heat through a reversible process, such as a high phase change. temperature. Suitable heat sensitive storage materials include silica gel, alumina, carbon, glass mat, fiberglass, minerals, from a metal or metal alloy, such as aluminum, silver and lead, and a cellulosic material, such as paper . Other suitable materials that release heat through a reversible phase change include paraffin, sodium acetate, naphthalene, wax, polyethylene oxide, a metal, metal salt, a mixture of eutectic salts or an alloy.

[0029] The heat sink or the heat reservoir can be arranged in such a way that they are directly in contact with the aerosol forming substrate and can transfer the stored heat directly to the substrate. Alternatively, the heat stored in the heat from the heat sink or reservoir can be transferred to the aerosol-forming substrate by means of a thermal conductor, such as a metal tube.

[0030] The electric heating element can heat the aerosol-forming substrate by means of conduction. The electric heating element can be at least partially in contact with the substrate, or the conveyor on which the substrate is deposited. Alternatively, the heat from the electric heating element can be conducted to the substrate by means of a heat conducting element.

[0031] Alternatively, the electric heating element can transfer heat to the ambient air that is sucked through the electrically heated smoke system during use, which in turn heats the aerosol-forming substrate by convection. Ambient air can be heated before passing through the aerosol-forming substrate.

[0032] In one embodiment, energy is supplied to the electric heater until the heating element or heater elements reach a temperature between about 250 ° C and 440 ° C, in order to produce an aerosol from aerosol-forming substrate. Any temperature sensor and control of a suitable circuit can be used in order to control the heating of the heating element or elements to reach a temperature between about 250 ° C and 440 ° C, including the use of one or more heaters. This is in contrast to conventional cigarettes, in which the combustion of tobacco and cigarette wrap can reach 800 ° C.

[0033] The aerosol forming substrate can be contained in a smoke article. During operation, the smoke article containing the aerosol forming substrate can be completely contained within the aerosol generating device. In this case, a user can blow on a nozzle of the aerosol generating device. A mouthpiece can be any portion of the aerosol generating device that is placed in a user's mouth in order to directly inhale an aerosol generated by the aerosol generating article or an aerosol generating device. The aerosol is transmitted to the user's mouth through the mouthpiece. Alternatively, during operation, the smoke article containing the aerosol-forming substrate may be partially contained within the aerosol generating device. In this case, the user can aspirate directly into the nozzle of the tobacco product.

[0034] The smoke article can be substantially cylindrical in shape. The smoking article can be lengthen substantially. The tobacco product can have a length and circumference substantially perpendicular to the length. The aerosol forming substrate can be substantially cylindrical in shape. The aerosol forming substrate can be substantially elongated. The aerosol forming substrate can also have a length and circumference substantially perpendicular to the length. The aerosol forming substrate can be received in the slide receptacle of the aerosol generating device in such a way that the length of the aerosol forming substrate is substantially parallel to the direction of the air flow in the aerosol generating device.

[0035] The tobacco product can have a total length of between approximately 30 mm and approximately 100 mm. The smoke product can have an outside diameter between about 5 mm and about 12 mm. The smoking article may comprise a filter plug. The filter plug may be located at the downstream end of the smoke article. The filter plug may be a cellulose acetate filter plug. The filter plug is approximately 7 mm long in one embodiment, but can be from about 5 mm to approximately 10 mm long.

[0036] In one embodiment, the smoking article has a total length of approximately 45 mm. The smoke product can have an outside diameter of approximately 7.2 mm. In addition, the aerosol forming substrate may be approximately 10 mm long. Alternatively, the aerosol forming substrate may be approximately 12 mm long. In addition, the diameter of the aerosol forming substrate can be between about 5 mm and about 12 mm. The smoking article may comprise an outer paper wrapper. In addition, the smoke article may comprise a separation between the aerosol forming substrate and the filter plug. The separation can be approximately 18 mm, but it can be in the range of approximately 5 mm to approximately 25 mm.

[0037] The aerosol forming substrate can be a solid aerosol forming substrate. Alternatively, the aerosol-forming substrate may comprise both solid and liquid components. The aerosol-forming substrate may comprise a tobacco-containing material, which contains volatile tobacco flavor compounds, which are released from the substrate after heating. Alternatively, the aerosol forming substrate may comprise a material other than tobacco. The aerosol-forming substrate may further comprise a first aerosol, which facilitates the formation of a dense and stable aerosol. Examples of suitable aerosol builders are glycerin and propylene glycol.

[0038] If the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may include, for example, one or more of: powder, granules, pellet, fragments, spaghetti, strips or leaves which contain one or more of the following: grass, tobacco leaf, tobacco rib fragments, reconstituted tobacco, homogenized tobacco, and extruded expanded tobacco. The solid aerosol forming substrate can be in loose form, or it can be supplied in a suitable container or cartridge. Optionally, the solid aerosol-forming substrate may contain the additional volatile tobacco flavor compounds or non-tobacco derivatives, to be released upon heating of the substrate. The solid aerosol-forming substrate may also contain capsules which, for example, include additional or non-tobacco tobacco and volatile aromatics, such capsules may melt while heating the solid aerosol-forming substrate.

[0039] As used herein, homogenized tobacco refers to the material formed by the agglomeration of tobacco particles. The homogenized tobacco can be in the form of a leaf. The homogenized tobacco material can have an aerosol content of, for example, more than 5% on a dry weight basis. The homogenized tobacco material may alternatively have an earlier aerosol content of between 5% and 30% by weight on a dry weight basis. The sheets of homogenized tobacco material can be formed by agglomerating tobacco particles obtained by grinding or otherwise fragmenting one or both of the blade tobacco leaves and tobacco stems. Alternatively, or in addition, sheets of homogenized tobacco material may comprise one or more of tobacco powder, tobacco fines and other particulate by-product tobacco products formed during, for example, treatment, handling and transportation tobacco. The sheets of homogenized tobacco material may comprise one or more intrinsic binders, that is, the endogenous tobacco binders, one or more extrinsic binders, which are the endogenous tobacco binders, or a combination thereof to help agglutinate the particulate tobacco. Alternatively, or in addition, sheets of homogenized tobacco material may comprise other additives, including, but not limited to, tobacco and non-tobacco derivatives, aerosol-forming fibers, humectants, plasticizers, flavorings, fillers, a aqueous solution and non-aqueous solvents and combinations thereof.

[0040] In a particularly preferred embodiment, the aerosol-forming substrate comprises a wrinkled sheet collected from homogenized tobacco material. As used herein, the term "wrinkled sheet" indicates a sheet having a plurality of substantially parallel grooves or wrinkles. Preferably, when the aerosol generating article has been assembled, the substantially parallel ribs or undulations extend along or parallel to the longitudinal axis of the aerosol generating article. This advantageously facilitates the meeting of the wrinkled sheet of homogenized tobacco material to form the aerosol forming substrate. However, it will be observed when wrinkling sheets of homogenized tobacco material for inclusion in the aerosol generating article may, alternatively or in addition have a plurality of substantially parallel grooves or undulations that are arranged at an acute or obtuse angle with respect to to the longitudinal axis of the article, when the aerosol generating article has been assembled from aerosol generating. In certain embodiments, the aerosol-forming substrate may comprise a wrinkled sheet of homogenized tobacco material that is substantially uniform and substantially textured across its entire surface. For example, the aerosol forming substrate may comprise a wrinkled sheet collected from homogenized tobacco material that comprises a plurality of substantially parallel grooves or undulations that are substantially evenly spaced across the width of the sheet.

[0041] Optionally, the solid aerosol forming substrate can be supplied or incorporated in a thermally stable vehicle. The vehicle can take the form of powder, granules, pellets, fragments, spaghetti, strips or leaves. Alternatively, the carrier can be a tubular carrier with a thin layer of solid substrate deposited on its inner surface, or on its outer surface, or on both its inner and outer surfaces. Such a tubular vehicle can be formed, for example, of paper, or paper-like material, a non-woven carbon fiber mat, a low-mass open-mesh wire mesh, or a perforated metal sheet or any other matrix of thermally stable polymer.

[0042] The solid aerosol-forming substrate can be deposited on the surface of the support, in the form of, for example, a sheet, foam, gel or paste. The solid aerosol-forming substrate can be deposited over the entire surface of the vehicle, or, alternatively, can be deposited in a pattern, in order to provide a non-uniform aroma release during use.

[0043] While reference is made to the solid aerosol forming substrates above, it will be apparent to one skilled in the art that other forms of aerosol forming substrate can be used with other modalities. For example, the aerosol forming substrate may be a liquid aerosol forming substrate. If a liquid aerosol forming substrate is provided, the aerosol generating device preferably comprises means for retaining the liquid. For example, the liquid aerosol-forming substrate can be kept in a container. Alternatively or in addition, the liquid aerosol-forming substrate can be absorbed into a porous carrier material. The porous support material can be made of any suitable absorbent buffer or body, for example, a foamed metal or plastic material, polypropylene, terylene (polyethylene terephthalate - PET), nylon or ceramic fibers. The liquid aerosol forming substrate may be retained in the porous carrier material, prior to the use of the aerosol generating device, or alternatively, the liquid aerosol forming substrate material may be introduced into the porous support material, during, or immediately before use. For example, the liquid aerosol forming substrate can be supplied in a capsule. The capsule shell preferably melts under heating and releases the liquid aerosol-forming substrate into the porous support material. The capsule can optionally contain a solid in combination with the liquid.

[0044] Alternatively, the carrier may be a fabric or bundle of nonwoven fibers, in which the tobacco components have been incorporated. The nonwoven fabric or bundle of fibers may comprise, for example, carbon fibers, natural cellulose fibers, cellulose derivatives or fibers.

[0045] The aerosol generating device may further comprise an air intake. The aerosol generating device may further comprise an air outlet. The aerosol generating device may further comprise a condensing chamber to allow the aerosol that has the desired characteristics to form.

[0046] The aerosol generating device is preferably a hand-held aerosol generating device that is comfortable for a user to hold between the fingers of a single hand. The aerosol generating device can be substantially cylindrical in shape. The aerosol generating device can have a polygonal cross section and a protruding button formed on one side: in this embodiment, the external diameter of the aerosol generating device can be between about 12.7 mm and about 13.65 mm measured from from a flat face to an opposing flat face; between about 13.4 mm and about 14.2 mm measured from an edge of an opposite end (that is, from the intersection of the two faces on one side of the aerosol generating device to a corresponding intersection on the other side ); and between about 14.2 mm and about 15 mm, measured from an upper part of the button to an opposite flat lower face. The length of the aerosol generating device can be between about 70 mm and 120 mm.

[0047] In another aspect of the specification, a method is presented for detecting a user by inhalation through an electrically heated aerosol generating device, the device comprising a heating element and a power supply for supply energy to the heating element, which comprises: controlling the energy supplied to the heating element of the power supply to maintain the heating element at a target temperature, and monitoring changes in the temperature of the heating element or the evolution of the energy supplied to the heating element. heating element to detect a change in air flow by the heating element indicative of a user inhalation.

[0048] The monitoring step may comprise monitoring a difference between the temperature of the heating element and the target temperature of detecting a change in the air flow by the heating element indicative of a user inhalation.

[0049] The method may further comprise the step of adjusting the target temperature when a change in airflow by the heating element indicative of a user by inhalation is detected. As described, the increased air flow brings more oxygen into contact with the substrate.

[0050] In another aspect of the specification, a computer program is presented which, when executed on a computer or other suitable processing device, performs the process according to the other aspect described above. The descriptive report includes modalities that can be used as a suitable software product to run on ae-rossol generation devices with a programmable controller, as well as the other necessary hardware elements.

[0051] The examples will now be described in detail with reference to the accompanying drawings, in which:

[0052] Figure 1 is a schematic drawing showing the gastrointestinal elements of an aerosol generating device according to a modality;

[0053] Figure 2 is a schematic diagram, which illustrates the elements of a control modality;

[0054] Figure 3 is a graph that illustrates the changes in the temperature of the heater and energy supplied during the suction of users according to another mode; and

[0055] Figure 4 illustrates a control sequence to determine whether a user aspiration is taking place in accordance with yet another modality.

[0056] In Figure 1, the interior of an embodiment of an aerosol generating device 100 is shown in a simplified manner. In particular, the elements of the aerosol generating device 100 are not designed to scale. The elements that are not relevant to the understanding of the modality discussed here have been omitted to simplify Figure 1.

[0057] The aerosol generating device 100 comprises a housing 10 and an aerosol-forming substrate 2, for example a cigarette. The aerosol-forming substrate 2 is pushed into the housing 10 to enter thermal proximity with the heating element 20. The aerosol-forming substrate 2 will release a variety of volatile compounds at different temperatures. Some of the volatile compounds released from the aerosol-forming substrate 2 are only formed during the heating process. Each volatile compound will be released above a characteristic release temperature. By controlling the maximum operating temperature of the aerosol generating device 100 to be below the relief temperature of some of the volatile compounds, the release or formation of these smoke constituents can be prevented.

[0058] In addition, the aerosol generating device 100 includes an electrical power source 40, for example, a rechargeable lithium-ion battery, from inside the box 10. The aerosol generating device 100 also includes a controller 30, which is connected to the heating element 20, the electrical supply 40, an aerosol forming substrate detector 32 and a user interface 36, for example, a graphical presentation or a combination of LED indicator lights that transmit the device information from 100 to a user.

[0059] The aerosol forming substrate detector 32 can detect the presence and identity of an aerosol forming substrate 2 in the thermal proximity to the heating element 20 and signals the presence of an aerosol forming substrate 2 with the controller 30. The provision of a substrate detector is optional.

[0060] Controller 30 controls user interface 36 to display system information, for example, battery power, temperature, aerosol status of substrate 2, other messages or combinations thereof.

[0061] Controller 30 further controls the maximum operating temperature of the heating element 20. The temperature of the heating element can be detected by a specific temperature sensor. Alternatively, in another mode, the temperature of the heating element is determined by monitoring its electrical resistance. The resistivity of a wire length depends on its temperature. Resistivity p increases with increasing temperature. The actual characteristic of the resistivity p will vary, depending on the exact composition of the alloy and the geometric configuration of the heating element 20, and an empirically determined relationship can be used in the controller. Thus, knowledge of resistivity p at any given time can be used to deduce the actual operating temperature of the heating element 20.

[0062] The resistance of the heating element R = V / I; where V is the voltage across the heater element and I is the current passing through the heating element 20, the resistance R depends on the configuration of the heating element 20, as well as the temperature, and is expressed by the following relationship:

[0063] Where p (T) is the temperature that depends on the resistivity, L is the length and the area S of the cross section of the heater element 20. L and S are fixed for a given heating element 20 and a configuration can be measured. Thus, for a given heating element design, R is proportional to p (T).

[0064] The resistivity p (T) of the heating element can be expressed in polynomial form as follows:

[0065] Where po is the resistivity at a reference temperature To e «and« 2 and are the polynomial coefficients.

[0066] Thus, knowing the length and the cross section of the heater element 20, it is possible to determine the resistance R, and therefore the resistivity for a given temperature, by measuring the heating element of voltage V and current I. A Temperature can be obtained simply from a search table for the characteristic resistivity against the temperature ratio of the heating element to be used or by evaluating the polynomial of equation (2) above. In one embodiment, the process can be simplified by representing resistivity p as a function of the temperature curve in one or more, preferably, two linear approximations in the temperature range applicable to tobacco. This simplifies the evaluation of the temperature at which it is desirable in a controller 30 that has limited computational resources.

[0067] Figure 2 is a block diagram illustrating the elements of the control device of Figure 1. Figure 2 also illustrates that the device is connected to one or more external devices 58, 60. Controller 30 includes a unit measuring unit 50 and a control unit 52. The measuring unit is configured to determine the resistance R of the heating element 20. The measuring unit 50 passes the resistance measurements to the control unit 52. the control unit 52 controls, then the battery power supply 40 to the heating element 20, alternating switch 54. The controller may comprise a microprocessor, as well as a separate electronic control circuit. In one embodiment, the microprocessor may include standard functionality, such as an internal clock, in addition to other functionality.

[0068] In a preparation of the temperature controller, a value for the target operating temperature of the aerosol generating device 100 is selected. The selection is based on the release temperatures of volatile compounds that should and should not be released. This predetermined value is then stored in the control unit 52. The control unit 52 includes a non-volatile memory 56.

[0069] Controller 30 controls the heating of the heating element 20, controlling the supply of electricity from the battery to the heating element 20. Controller 30 allows only for the supply of energy to the heating element 20, if the aerosol forming substrate detector 32 has detected an aerosol forming substrate 20 and the user has activated the device. By switching switch 54, power is supplied as a pulsed signal. The width of the pulse or signal duty cycle can be modulated by the control unit 52 to change the amount of energy supplied to the heating element. In one embodiment, the duty cycle can be limited to 6080%. This can provide additional security and prevent a user from inadvertently raising the compensated temperature of the heater in such a way that the substrate reaches a temperature above the combustion temperature.

[0070] In use, controller 30 measures the resistivity p of the heating element 20. The controller 30 then converts the resistivity of the heating element 20 to a value for the actual operating temperature of the heating element, using comparison of the resistivity p measured with the research table. This can be done inside the measuring unit 50 or by the control unit 52 itself. In the next step, the controller 30 compares the actual temperature of the derivative operation with the target operating temperature. Alternatively, the temperature values of the heating profile are pre-converted to resistance values so that the controller regulates the resistance instead of the temperature, which prevents real-time computations from converting the temperature resistance during the experiment of smoke.

[0071] If the actual operating temperature is below the target operating temperature, then the control unit 52 supplies the heating element 20 with additional electrical energy in order to raise the actual operating temperature of the heating element 20. If the actual operating temperature is higher than the target operating temperature, the control unit 52 reduces the electrical energy supplied to the heating element 20 in order to lower the actual operating temperature back to the target operating temperature.

[0072] The control unit can implement any control technique suitable for regulating the temperature, such as a simple thermostatic return cycle or a proportional integral, derivative control (PID) technique.

[0073] The temperature of the heating element 20 is not only affected by the energy supplied to it. The flow of air through the heating element 20 cools the heating element, reducing its temperature. This cooling effect can be exploited to detect changes in airflow through the device. The temperature of the heating element, as well as its electrical resistance, will decrease when the air flow increases before the control unit 52 brings the heating element back to the target temperature.

[0074] Figure 3 shows a typical evolution of heating element temperature and the energy applied when using an aerosol generating device of the type shown in Figure 1. The level of energy supplied is shown as a line 60 and the temperature heating element as line 62. The target temperature is shown as a dotted line 64.

[0075] An initial period of high energy is required at the beginning of use in order to bring the heating element up to the target temperature as quickly as possible. Once the target temperature has been reached, the applied energy drops to the level necessary to maintain the heating element at the target temperature. However, when the user aspirates on the substrate 2, the air is extracted after the heating element and cools it below the target temperature. This is shown as a characteristic 66 in Figure 3. To return the heating element 20 to the target temperature, a corresponding increase in applied force occurs, as characteristic 68 in Figure 3. This pattern is repeated throughout the use of the device, in this case. example, a smoking session, in which four inhalations are considered.

[0076] By detecting temporary changes in temperature or energy, or in the rate of change in temperature or energy, user puffs or other airflow events can be detected. Figure 4 illustrates an example of a control process, using a Schmitt trigger stabilization approach, which can be used within control unit 52 to determine when a puff is taking place. The process in Figure 4 is based on detecting changes in the temperature of the element heater. In step 400, an arbitrary state variable, which is initially set to 0, is changed to three quarters of its original value. In step 410 a delta value is determined which is the difference between a measured temperature of the heating element and the target temperature. Steps 400 and 410 can be performed in reverse order, or in parallel. In step 415 the delta value is compared to a delta limit value. If the delta value is greater than the delta threshold, then the state variable is increased by a quarter before going to step 425. This is shown with step 420. If the delta value is less than the threshold a state variable is unchanged and the process moves to step 425. the state variable is then compared to a state threshold. The state limit value used is different depending on whether the device is determined by how long it is in a suction or non-suction state. In step 430 the control unit determines whether the device is in a suction or non-suction state. Initially, that is, in a first control cycle, the device is considered to be in a non-aspiration state.

[0077] If the device is in a non-suction state, the state variable is compared to a high limit state in step 440. If the state variable is greater than the high limit state, then the device is determined to be in a suction state. If not, he is determined to remain in a state of non-aspiration. In both cases, the process moves to step 460 and then returns to 400.

[0078] If the device is in a suction state the state variable is compared to a LOW state threshold in step 450. If the state variable is less than the LOW state threshold, then the device is determined to be in a state of non-aspiration. If not, he is determined to remain in a breathless state. In both cases, the process moves to step 460 and then returns to step 400.

[0079] The value of the high and low limit values directly influence the number of cycles during the process are necessary to make the transition between the aspiration and non-aspiration states, and vice versa. In this way the very short-term fluctuations in temperature and noise in the system, which are not the result of a user sponge, can be prevented from being detected as an aspiration. Short fluctuations are effectively filtered. However, the number of cycles required is desirably chosen so that the suction detection transition can occur before the device compensates for the temperature drop by increasing the energy supplied to the heating element. Alternatively, the controller could suspend the compensation process, while considering the decision to perform an aspiration or not. In one example, HIGH = 0.06 and LOW = 0.94, which means that the system needs to go through at least 10 iterations when the delta value is greater than the delta limit to go from not aspirating to aspirating.

[0080] The system illustrated in Figure 4 can be used to provide a number of aspirations and, if the controller includes a clock, an indication of the time at which each aspiration occurs. The suction and non-suction states can also be used to dynamically control the target temperature. Increased air flow brings more oxygen into contact with the substrate. This increases the likelihood of combustion of the substrate at a given temperature. Combustion of the substrate is undesirable. Thus, the target temperature can be reduced when an aspiration state is determined, in order to reduce the likelihood of combustion of the substrate. The target temperature can then be returned to its original value when a non-suction state is determined.

[0081] The process shown in Figure 4 is just one example of an aspiration detection process. For example, processes similar to those illustrated in Figure 4 can be carried out using the applied energy as a measure or using the rate of change of temperature or the rate of change of applied energy. It is also possible to use a process similar to the one shown in Figure 4, but using only a single state threshold, instead of different high and low thresholds.

[0082] In addition to being useful for the dynamic control of the aerosol generating device, the aspiration detection data determined by the controller 30 can be useful for analysis purposes, for example, in clinical trials or in the maintenance of the device and processes of conception. Figure 2 illustrates the connection of controller 30 to an external device 58. Aspiration and time count data can be exported to external device 58 (along with any other captured data) and can also be transmitted from the device 58 to other external processing or data storage devices 60. The aerosol generating device may include any suitable data output means. For example, the aerosol generating device may include a wireless radio, connected to memory controller 30, or 56, or a universal serial bus (USB), connected to memory controller 30 or 56. Alternatively, the device Aerosol generator can be configured to transfer data from the memory of an external memory to a battery charging device each time the aerosol generating device is recharged through suitable data connections. The battery charging device can provide a larger amount of memory for long-term storage of the suction data and can subsequently be connected to a suitable data processing device or to a communications network. In addition, data as well as instructions for controller 30 can be loaded, for example, to control unit 52, when controller 30 is connected to an external device 58.

[0083] Additional data may also be collected during the operation of the aerosol generating device 100 and transferred to the external device 58 These data may include, for example, a serial number or other identification data of the aerosol generating device; the time at the beginning of the smoking session; the moment of the end of the smoking session; and information related to the reason for ending a smoking session.

[0084] In one embodiment, a serial number or other identification data, or tracking information, associated with the aerosol generating device 100 can be stored within controller 30. For example, such tracking information can be stored in memory 56. As the aerosol generating device 100 may not always be connected to the same external device 58 for billing or data transfer purposes, this tracking information can be exported to processing or data storage devices 60 and came together to provide a more complete picture of user behavior.

[0085] Now, it will be evident to a person skilled in the art that knowledge of the operating time of the aerosol generating device, such as the starting and ending point of the smoking session, can also be captured using the methods and the devices described here. For example, using the clock functionality of controller 30 or control unit 52, the start time of the smoking session can be captured and stored by controller 30. Likewise, a stop time can be recorded when the user or the aerosol generating device 100 ends the session, stopping power to the heating element 20. the accuracy of such a start and end can be even greater if more and more accurate is sent to the controller 30 by the external device 58 to correct any loss or inaccuracy. For example, when connecting controller 30 to external device 58, device 58 can interrogate the internal clock function of controller 30, compare the received time value with a clock provided inside external device 58 or one or more external treatment or data storage devices 60, and provide an updated clock signal to controller 30.

[0086] The reason for ending a smoking session or the operation of the aerosol generating device 100 can also be identified and captured. For example, control unit 52 may include a look-up table, which includes various reasons for the end of the session or the smoking operation. An exemplary list of these reasons is provided here.

[0087] The table above provides a number of exemplary reasons why the operation or a smoking session may end. It will now be apparent to a person skilled in the art, using various indications provided by the measuring unit 50 and the control unit 52 provided in the controller 30, either alone or in combination with the recorded indications, in response to the controller 30 heating control. heating element 20, controller 30 may assign session codes with a reason for ending the operation of an aerosol generating device of 100 or a smoke session with the use of such a device. Other reasons that can be determined from the available data, using the methods and devices described above will now be evident to a person skilled in the art and can also be implemented using the methods and devices described here, without deviating from the scope or spirit of the present specification and the exemplary modalities described here.

[0088] Other data relating to the operation of a user of the aerosol generating device 100 can also be determined using the methods and apparatus described here. For example, the user's consumption of aerosol derivatives can be accurately approximated because the aerosol generating device 100 described herein can precisely control the temperature of the heating element 20, and because the data can be collected by the controller 30, as well as units 50 and 52 provided within controller 30, an accurate profile of the actual use of device 100 during a session can be obtained.

[0089] In an exemplary embodiment, the session data captured by the controller 30 can be compared with the data determined during controlled sessions to further increase the user's understanding of the use of the device 100. For example, first, the collection of data data using a smoke machine under controlled environmental conditions and measurement data, such as suction number, blowing volume, suction interval, and heating element resistivity, a database can be built that offers, for example, example, nicotine levels or other benefits provided under experimental conditions. This experimental data can be compared with the data collected by the controller 30 during actual use and used to determine, for example, information about the quantity of a final product that the user has inhaled. In one embodiment, these experimental data can be stored on one or more of the devices 60 and further comparison and data processing can take place on one or more devices 60.

[0090] As additional environmental data is needed to accurately compare actual user data and experimental data, the control unit 52 may include additional functionality to provide such data. For example, the control unit 52 may include a humidity data sensor or the ambient temperature and humidity sensor or ambient temperature data may be included as part of the data, possibly provided for the external device 58. The use of the device it can also be analyzed to determine which experimentally determined data most closely matches usage behavior, for example, in terms of duration and frequency of inhalation and number of inhalations. The experimental data with the most closely related usage behavior can then be used as the basis for further analysis and display.

[0091] It will be evident to a person skilled in the art, that with the use of the methods and devices discussed here, almost any desired information can be captured by it and comparison to experimental data is possible, and various attributes associated with the operation of a user of the aerosol generating device 100 are accurately approximated.

[0092] The exemplary modalities described above illustrate, but are not limiting. Considering the exemplary modalities discussed above, other modalities consistent with the exemplary modalities above will now be evident to a person skilled in the art.

Claims (13)

1. Aerosol-generating electric smoking device (100) configured for inhalation by a user of a generated aerosol, the device comprising: a heating element (20) configured to heat an aerosol-forming substrate (2); a power source (40) connected to the heating element (20); and a controller (30) connected to the heating element (20) and the power source (40), where the controller is configured to control the energy supplied to the heating element from the power source to maintain the heating element at a temperature - target, and characterized by the fact that it is configured to monitor changes in a temperature of the heating element or changes in the energy supplied to the heating element to detect a change in air flow after the heating element indication of a user inhalation. 2. Aerosol-generating electric smoking device (100) according to claim 1, characterized by the fact that the controller (30) is configured to monitor a difference between the temperature of the heating element (20) and the target temperature to detect a change in airflow after the indication of the heating element for a user inhalation. 3. Aerosol-generating electric smoking device (100) according to claim 2, characterized by the fact that the controller (30) is configured to monitor whether a difference between the temperature of the heating element (20) and the target temperature exceeds a threshold to detect a change in airflow after indicating the heating element of a user inhalation. 4. Aerosol-generating electric smoking device (100) according to claim 3, characterized by the fact that the controller (30) is configured to monitor whether a difference between the temperature of the heating element (20) and the target temperature exceeds a threshold for a predetermined period of time or for a predetermined number of measurement cycles to detect a change in airflow after indicating the heating element of a user inhalation. An aerosol-generating electric smoking device (100) according to any one of claims 1 to 4, characterized in that the controller (30) is configured to monitor a difference between the energy supplied to the heating element (20) and an expected energy level. An aerosol-generating electric smoking device (100) according to any one of claims 1 to 5, characterized in that the controller (30) is configured to compare a rate of change of temperature or a rate of change of energy provided with a threshold level. Aerosol-generating electric smoking device (100) according to any one of claims 1 to 6, characterized in that the controller (30) is configured to adjust the energy supplied to the heating element (20) when a change in air flow after the heating element is detected. Aerosol-generating electric smoking device (100) according to any one of claims 1 to 7, characterized in that the controller (30) is configured to adjust the target temperature when a change in airflow after the heater is detected. Aerosol-generating electric smoking device (100) according to any one of claims 1 to 8, characterized in that the controller (30) is configured to monitor the temperature of the heating element (20) based on a measurement the electrical resistance of the heating element (20). Aerosol-generating electric smoking device (100) according to any one of claims 1 to 9, characterized in that the device (100) includes data output means and in which the controller (30) is configured to provide a record of each change detected in the air flow after indicating the heating element of a user inhalation to the data output means. A method for detecting user inhalation via an electrically heated aerosol-generating electric smoking device (100) as defined in any of claims 1 to 10, the device comprising a heating element (20) and a power source ( 40) to supply energy to the heating element (20), the method characterized by the fact that it comprises controlling the energy supplied to the heating element (20) from the energy source to maintain the heating element at a target temperature, and to monitor changes in the temperature of the heating element or changes in the energy supplied to the heating element (20) to detect a change in the air flow that passes the heating element indicating a user inhalation. 12. Method according to claim 11, characterized in that the step of monitoring comprises monitoring a difference between the temperature of the heating element (20) and the target temperature to detect a change in the air flow that passes the heating element indicative of a user inhalation. 13. Method according to claim 11 or 12, characterized by the fact that it still comprises the step of adjusting the target temperature when a change in the air flow that passes the heating element indicative of a user inhalation is detected.

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